Selenium

How much do you need daily?

Women need 60 micrograms a day and men need 75 micrograms per day.

Are we getting enough?

The 2016 National Diet and Nutrition Survey found that a substantial proportion of adults had intakes below the lower recommended level for selenium. A third of teenagers and working-age adults are failing to meet even low targets and two out of five older adults are also not getting enough selenium.

Why do we need it?

Selenium is a key part of our cell defence mechanism and acts as an antioxidant – protecting cell membranes and DNA from damage. It is also needed for the correct functioning of the thyroid gland and plays a role in fertility – selenium helps protect the ovaries and sperm from free radial damage.

It’s naturally found in the soil but levels vary – hence the selenium content of plant foods varies accordingly.

There have been claims that selenium can help prevent certain types of cancer but these claims have not been substantiated.

There’s no benefit from taking extra selenium – a healthy diet will provide enough – and high intakes can cause health issues such as hair and nail loss or brittleness, skin rashes or lesions, nausea, irritability, tiredness and even mild nerve damage. The safe intake has been established as 450 micrograms (maximum) a day.

Do I need a supplement?

No, a healthy vegan diet containing the above foods on a daily basis will cover your needs.

The best plant sources

The best plant sources of selenium include Brazil nuts, sunflower seeds, sesame seeds, wholegrains, tofu, asparagus and mushrooms.

The main plant-based sources of selenium in the UK diet are bread and cereals. The amount contained in 100 grams of Brazil nuts can range from 85-690 micrograms per 100 grams. Consuming just two Brazil nuts a day for 12 weeks can increase the amount of selenium in the blood by over 60 per cent. So, including Brazil nuts in the diet could avoid the need for supplements. 

Signs of deficiency

hair loss, fingernail discoloration, low immunity, tiredness, inability to concentrate, reproductive problems, hypothyroidism (low function of the thyroid); extreme deficiency can lead to Keshan disease (cardiomyopathy) or Kashin-Beck disease (a type of osteoarthritis).